Reversal of dentin bonding to bleached teeth

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Restorative Dentistry

Background:

• Dental bleaching agents can compromise the bond strength of resin composites to tooth structure.
• A waiting period is often recommended after bleaching before dental restorations are placed.

Purpose of the Study:

• To investigate the efficacy of antioxidant applications in restoring the bond strength of resin composites to bleached dentin.
• To compare the effects of different bleaching agents and antioxidant treatments on bond strength.

Main Methods:

• Ninety human teeth underwent various bleaching treatments (gel or sol) with or without antioxidants (sodium ascorbate or butylhydroxyanisole).
• Control groups included untreated teeth and teeth immersed in artificial saliva.
• Shear bond strength of resin composite restorations was measured using a universal testing machine.

Main Results:

• Bleaching significantly reduced dentin bond strength compared to the control group.
• Antioxidant treatments, particularly 10% sodium ascorbate, effectively reversed the bond strength reduction caused by bleaching.
• Bond strength in teeth treated with antioxidants after bleaching was comparable to those stored in artificial saliva for seven days.

Conclusions:

• Antioxidant application is a viable strategy to mitigate the negative effects of dental bleaching on resin composite bond strength.
• Sodium ascorbate shows significant potential in restoring bond strength to bleached dentin, allowing for timely restoration placement.